The present invention relates to a tire monitoring unit for use in an apparatus for monitoring tire conditions, and more particularly to a tire monitoring unit having a structure adapted to be appropriately mounted on a wheel rim of a vehicle.
Heretofore, there are known tire condition monitoring apparatuses capable of monitoring tire conditions, such as pneumatic pressure or the like, of a vehicle tire, and various tire monitoring units for use in those apparatuses have been proposed. Among such known apparatuses, there is known a tire monitoring unit with a transmitting function, which is provided with electronic parts, a battery, an antenna, and so on. In general, the tire monitoring unit is placed in a space between a wheel rim and a tire, and normally mounted on the rim by a pin connection or welding. In U.S. Pat. No. 6,549,125 B2, for example, a tire condition sensor unit is disclosed that is incorporated in a box placed inside a space delineated by the rim and the tire. The box is fastened to a pin permanently joined to the rim and protruding toward an inside of the tire. For example, it is disclosed that a housing box is fastened by a retainer to a stud welded to the rim.
Likewise, U.S. Pat. No. 6,672,150 B2 discloses mounting a housing for a tire pressure sensor on a wheel rim, with a body extended by a plurality of elastically deformable wings of a variable height being fixed by a snap-on attachment to a stud fixed to the rim. Various examples of mechanisms for mounting the snap-on attachment to the stud are disclosed. U.S. Pat. No. 6,694,807 B2, discloses a wheel rim having a tire sensor for a pneumatic tire, wherein a base seat is fixed on a rim portion having a valve rod, at a location other than the location of the valve rod, and a sensor is embedded in and attached to the base seat for sensing conditions of the pneumatic tire and transmitting signals. The base seat is formed with a bottom and two opposing walls spaced from each other and extending upward from the bottom. The arrangement includes hooks and flaps to hold the tire sensor at opposite sides thereof in a circumferential direction of the rim.